This work aims to develop and characterize a hybrid composite material with two particles of the same size. As reinforcing particles, the hulls of palm nuts and coconut are chosen. Hybrid composite material composites...This work aims to develop and characterize a hybrid composite material with two particles of the same size. As reinforcing particles, the hulls of palm nuts and coconut are chosen. Hybrid composite material composites in the form of specimens were produced by molding at 10%, 20% and 30% mass fractions in various sizes (0.63<span style="font-family:;" "=""> </span><span style="font-family:Verdana;">mm, 1.25</span><span style="font-family:;" "=""> </span><span style="font-family:Verdana;">mm and 2.5</span><span style="font-family:;" "=""> </span><span style="font-family:Verdana;">mm). The samples were physically characterized (water absorption rate, moisture content, actual, theoretical and apparent density) and mechanical in 3-point flexion. The main results are: the highest and minimum water absorption rate are respectively 3.57% and 0.67% for respectively particle sizes 1.25</span><span style="font-family:;" "=""> </span><span style="font-family:Verdana;">mm (sample P10C30) and 0.67% in the size of 0.63</span><span style="font-family:;" "=""> </span><span style="font-family:Verdana;">mm (sample P10C10). The moisture content varies from 0.64 to 7.14% respectively for the P20C20 (2.5 mm) and P10C30 (2.5 mm) samples. The maximum and minimum real density are 1340,518</span><span style="font-family:;" "=""> </span><span style="font-family:;" "=""><span style="font-family:Verdana;">Kg/m</span><sup><span style="font-family:Verdana;">3</span></sup><span style="font-family:Verdana;"> and 1055.981</span></span><span style="font-family:;" "=""> </span><span style="font-family:;" "=""><span style="font-family:Verdana;">Kg/m</span><sup><span style="font-family:Verdana;">3</span></sup><span style="font-family:Verdana;">, for respectively the composites of particles sizes 1.25</span></span><span style="font-family:;" "=""> </span><span style="font-family:Verdana;">mm (P20C10) and 0.63</span><span style="font-family:;" "=""> </span><span style="font-family:;" "=""><span style="font-family:Verdana;">mm (sample P20C20). The minimum real density is Its </span><span><span style="font-family:Verdana;">maximum theoretical density is 1194.949 Kg/m</span><sup><span style="font-family:Verdana;">3</span></sup><span style="font-family:Verdana;"> (for samples P20C10,</span></span><span style="font-family:Verdana;"> P10C10 and P30C10);however, the minimum is 1189.966 Kg/m</span><sup><span style="font-family:Verdana;">3</span></sup><span style="font-family:Verdana;"> (P10C20 and P20C20). The bulk density varies from 933.28</span></span><span style="font-family:;" "=""> </span><span style="font-family:;" "=""><span style="font-family:Verdana;">Kg/m</span><sup><span style="font-family:Verdana;">3</span></sup><span style="font-family:Verdana;"> to 1176.1</span></span><span style="font-family:;" "=""> </span><span style="font-family:;" "=""><span style="font-family:Verdana;">Kg/m</span><sup><span style="font-family:Verdana;">3</span></sup><span style="font-family:Verdana;">, respectively, in sizes from 2.5</span></span><span style="font-family:;" "=""> </span><span style="font-family:Verdana;">mm (P10C30) to 0.63</span><span style="font-family:;" "=""> </span><span style="font-family:;" "=""><span style="font-family:Verdana;">mm (for P10C30). As for the mechanical characteristics, the Modulus of Elasticity (MOE) varies from 25.664 GPa to 25.759 GPa, respectively, the samples P10C10 (1.25 mm) and P10C20 (2.5 mm). The MOE values describe a parabola whose peak is reached when the palm shell loads are 20%, that is to say P20C10, whatever the particle size distribution. In resilience, samples with small particles are more resilient with a maximum value of 22.49 J/cm</span><sup><span style="font-family:Verdana;">2</span></sup><span style="font-family:Verdana;"> and a minimum value of 4.45 J/cm</span><sup><span style="font-family:Verdana;">2</span></sup><span style="font-family:Verdana;"> to verify the principles of Hall-Petch’s law.</span></span>展开更多
Activated carbons (ACs) calcined at 400˚C, 500˚C, and 600˚C (AC-400, AC-500, and AC-600) were prepared using palm nut shells from Gabon as raw material and zinc chloride (ZnCl2) as a chemical activating agent. Prepare...Activated carbons (ACs) calcined at 400˚C, 500˚C, and 600˚C (AC-400, AC-500, and AC-600) were prepared using palm nut shells from Gabon as raw material and zinc chloride (ZnCl2) as a chemical activating agent. Prepared ACs were characterized by physisorption of nitrogen (N2), determination of diode and methylene blue numbers for studies of porosity and by quantification and determination of surface functional groups and pH at point of zero charge (pHpzc) respectively, for studies of chemical properties of prepared ACs. Then, effects of calcination temperature (Tcal) on porosity and chemical properties of prepared ACs were studied. The results obtained showed that when the calcination temperature increases from 500˚C to 600˚C, the porosity and chemical properties of prepared ACs are modified. Indeed, the methylene blue and iodine numbers determined for activated carbons AC-400 (460 and 7.94 mg·g−1, respectively) and AC-500 (680 and 8.90 mg·g−1, respectively) are higher than those obtained for AC-600 (360 and 5.75 mg·g−1, respectively). Compared to the AC-500 adsorbent, specific surface areas (SBET) and microporous volume losses for AC-600 were estimated to 44.7% and 45.8%, respectively. Moreover, in our experimental conditions, the effect of Tcal on the quantities of acidic and basic functional groups on the surface of the ACs appears negligible. In addition, results of the pHpzc of prepared ACs showed that as Tcal increases, the pH of the adsorbents increases and tends towards neutrality. Indeed, a stronger acidity was determined on AC-400 (pHpzc = 5.60) compared to those on AC-500 and AC-600 (pHpzc = 6.85 and 6.70, respectively). Also according to the results of porosity and chemical characterizations, adsorption being a surface phenomenon, 500˚C appears to be the optimal calcination temperature for the preparation of activated carbons from palm nut shells in our experimental conditions.展开更多
This study was conducted to valorize four sources of fiber (Gliricidia sepium, Leucaena leucocephala, Moringa oleifera and palm nut fibers) in animal production. The experiments were carried out on 128 rabbits divided...This study was conducted to valorize four sources of fiber (Gliricidia sepium, Leucaena leucocephala, Moringa oleifera and palm nut fibers) in animal production. The experiments were carried out on 128 rabbits divided into 4 batches of 32 animals, reared for 8 weeks under the same conditions. Each batch was subdivided into two subgroups, one fed with a complete diet (a diet containing one of the fiber sources and served all day) and the other with the same diet separated from the fiber source (served at 9 a.m. and supplemented with the fiber source at 4 p.m.). Eight (8) experimental rations were, respectively, tested on the subgroups: complete feed Gliricidia sepium (CFG);supplemented feed Gliricidia sepium (SFG);complete feed Leucaena leucocephala (CFL);supplemented feed Leucaena leucocephala (SFL);complete feed Moringa oleifera (CFM);supplemented feed Moringa oleifera (SFM);complete feed palm nut fiber (CFF);supplemented feed palm nut fiber (SFF). In each subgroup, 4 rabbits were slaughtered at 15 weeks of age for a total of 32 rabbits. Physico-chemical parameters were evaluated on the feed and the meat. Data were analyzed using SAS 2013 software. Fiber content was similar (p > 0.05) for complete feeds. Fat content was high (p < 0.001) for the palm nuts fiber (27.34%) and the CFF feed (11.36%). Feeding rabbits with G. sepium leaves or palm nut fiber continuously increased the fat content of the meat in contrast to sequential feeding. Meat quality was also better when the fiber source was used in the feed of the rabbits in the evening.展开更多
The purpose of this study is to compare the results of chemical analysis of two types of activated from the pyrolysis of bull horn and that of cow. Six samples were used to measure pH, carbon, calcium and to determine...The purpose of this study is to compare the results of chemical analysis of two types of activated from the pyrolysis of bull horn and that of cow. Six samples were used to measure pH, carbon, calcium and to determine adsorbent power. The pH was measured at a temperature of 20˚C using an “ANION 7010 ionomer” pH meter, the carbon (C) content was analyzed using a “EURO EA 3000” analyzer. and the electronic balance: “Sartorius CP-2P”, calcium (Ca) was analyzed using a DFS-8 spectrograph. For the adsorbency test, the 0.15% methylene blue R solution was used. At the end of this study, we found that the activated carbon from the bull horn demonstrated a carbon content that is higher than that of the cow horn (20.79% against 15.63%), activated carbon of cow horn is richer in calcium than that of bull horn (16.27% against 3.69%) and then the pH. The cow horn is higher than that of the bull horn (7.43 versus 6.5). For the adsorbent power, the sample (75% bull horn and 25% cow horn) was recorded with the greatest adsorbent power. Thus, from this study, it can be recommended as an activated carbon antidote to be used for poisonings treatment.展开更多
This work investigated the removal, kinetics and thermodynamics of iron(II) ions (Fe(II)) by adsorption in static and dynamic conditions in aqueous media on activated carbons (AC-i30min, AC-i1h, and AC-i24h), prepared...This work investigated the removal, kinetics and thermodynamics of iron(II) ions (Fe(II)) by adsorption in static and dynamic conditions in aqueous media on activated carbons (AC-i30min, AC-i1h, and AC-i24h), prepared from palm nut shells collected in the city of Franceville to Gabon, using potassium hydroxide (KOH) as the activating agent. Results on the elimination of Fe(II) in static and dynamic adsorption on prepared activated carbons (ACs) showed that the AC-i24h adsorbent has the best Fe(II) adsorption capacities at saturation (Qsat). The Qsat obtained on AC-i24h in static and dynamic conditions (17.87 and 10.38 mg/g, respectively) were higher than those of AC-i30min (13.89 and 5.54 mg/g respectively) and AC-i1h (14.92 and 8.64 mg/g respectively). Moreover, the static adsorption was more effective in the removal of Fe(II) ions in aqueous media in our experimental conditions. The percentage removal (%E) of Fe(II) obtained on prepared activated carbons in static conditions was better than those obtained in dynamic conditions, especially on AC-i24h, where the %E was 89.27% in static and 61.56% in dynamic. In kinetics, results showed that the pseudo-second-order kinetic model best described the adsorption mechanisms of Fe(II) on prepared activated carbons in static adsorption, with mainly of chemisorption on the solid surfaces. However, in dynamic conditions, the pseudo-first-order kinetic model was more suitable. In addition to the weak interactions between Fe(II) and the activated carbon surfaces, strong interactions (chemisorption) were also observed. Also, thermodynamic data obtained on AC-i24h in static adsorption indicated that the adsorption of Fe(II) was spontaneous and increased with temperature (ΔG˚ H˚ = 503.54 KJ/mol).展开更多
文摘This work aims to develop and characterize a hybrid composite material with two particles of the same size. As reinforcing particles, the hulls of palm nuts and coconut are chosen. Hybrid composite material composites in the form of specimens were produced by molding at 10%, 20% and 30% mass fractions in various sizes (0.63<span style="font-family:;" "=""> </span><span style="font-family:Verdana;">mm, 1.25</span><span style="font-family:;" "=""> </span><span style="font-family:Verdana;">mm and 2.5</span><span style="font-family:;" "=""> </span><span style="font-family:Verdana;">mm). The samples were physically characterized (water absorption rate, moisture content, actual, theoretical and apparent density) and mechanical in 3-point flexion. The main results are: the highest and minimum water absorption rate are respectively 3.57% and 0.67% for respectively particle sizes 1.25</span><span style="font-family:;" "=""> </span><span style="font-family:Verdana;">mm (sample P10C30) and 0.67% in the size of 0.63</span><span style="font-family:;" "=""> </span><span style="font-family:Verdana;">mm (sample P10C10). The moisture content varies from 0.64 to 7.14% respectively for the P20C20 (2.5 mm) and P10C30 (2.5 mm) samples. The maximum and minimum real density are 1340,518</span><span style="font-family:;" "=""> </span><span style="font-family:;" "=""><span style="font-family:Verdana;">Kg/m</span><sup><span style="font-family:Verdana;">3</span></sup><span style="font-family:Verdana;"> and 1055.981</span></span><span style="font-family:;" "=""> </span><span style="font-family:;" "=""><span style="font-family:Verdana;">Kg/m</span><sup><span style="font-family:Verdana;">3</span></sup><span style="font-family:Verdana;">, for respectively the composites of particles sizes 1.25</span></span><span style="font-family:;" "=""> </span><span style="font-family:Verdana;">mm (P20C10) and 0.63</span><span style="font-family:;" "=""> </span><span style="font-family:;" "=""><span style="font-family:Verdana;">mm (sample P20C20). The minimum real density is Its </span><span><span style="font-family:Verdana;">maximum theoretical density is 1194.949 Kg/m</span><sup><span style="font-family:Verdana;">3</span></sup><span style="font-family:Verdana;"> (for samples P20C10,</span></span><span style="font-family:Verdana;"> P10C10 and P30C10);however, the minimum is 1189.966 Kg/m</span><sup><span style="font-family:Verdana;">3</span></sup><span style="font-family:Verdana;"> (P10C20 and P20C20). The bulk density varies from 933.28</span></span><span style="font-family:;" "=""> </span><span style="font-family:;" "=""><span style="font-family:Verdana;">Kg/m</span><sup><span style="font-family:Verdana;">3</span></sup><span style="font-family:Verdana;"> to 1176.1</span></span><span style="font-family:;" "=""> </span><span style="font-family:;" "=""><span style="font-family:Verdana;">Kg/m</span><sup><span style="font-family:Verdana;">3</span></sup><span style="font-family:Verdana;">, respectively, in sizes from 2.5</span></span><span style="font-family:;" "=""> </span><span style="font-family:Verdana;">mm (P10C30) to 0.63</span><span style="font-family:;" "=""> </span><span style="font-family:;" "=""><span style="font-family:Verdana;">mm (for P10C30). As for the mechanical characteristics, the Modulus of Elasticity (MOE) varies from 25.664 GPa to 25.759 GPa, respectively, the samples P10C10 (1.25 mm) and P10C20 (2.5 mm). The MOE values describe a parabola whose peak is reached when the palm shell loads are 20%, that is to say P20C10, whatever the particle size distribution. In resilience, samples with small particles are more resilient with a maximum value of 22.49 J/cm</span><sup><span style="font-family:Verdana;">2</span></sup><span style="font-family:Verdana;"> and a minimum value of 4.45 J/cm</span><sup><span style="font-family:Verdana;">2</span></sup><span style="font-family:Verdana;"> to verify the principles of Hall-Petch’s law.</span></span>
文摘Activated carbons (ACs) calcined at 400˚C, 500˚C, and 600˚C (AC-400, AC-500, and AC-600) were prepared using palm nut shells from Gabon as raw material and zinc chloride (ZnCl2) as a chemical activating agent. Prepared ACs were characterized by physisorption of nitrogen (N2), determination of diode and methylene blue numbers for studies of porosity and by quantification and determination of surface functional groups and pH at point of zero charge (pHpzc) respectively, for studies of chemical properties of prepared ACs. Then, effects of calcination temperature (Tcal) on porosity and chemical properties of prepared ACs were studied. The results obtained showed that when the calcination temperature increases from 500˚C to 600˚C, the porosity and chemical properties of prepared ACs are modified. Indeed, the methylene blue and iodine numbers determined for activated carbons AC-400 (460 and 7.94 mg·g−1, respectively) and AC-500 (680 and 8.90 mg·g−1, respectively) are higher than those obtained for AC-600 (360 and 5.75 mg·g−1, respectively). Compared to the AC-500 adsorbent, specific surface areas (SBET) and microporous volume losses for AC-600 were estimated to 44.7% and 45.8%, respectively. Moreover, in our experimental conditions, the effect of Tcal on the quantities of acidic and basic functional groups on the surface of the ACs appears negligible. In addition, results of the pHpzc of prepared ACs showed that as Tcal increases, the pH of the adsorbents increases and tends towards neutrality. Indeed, a stronger acidity was determined on AC-400 (pHpzc = 5.60) compared to those on AC-500 and AC-600 (pHpzc = 6.85 and 6.70, respectively). Also according to the results of porosity and chemical characterizations, adsorption being a surface phenomenon, 500˚C appears to be the optimal calcination temperature for the preparation of activated carbons from palm nut shells in our experimental conditions.
文摘This study was conducted to valorize four sources of fiber (Gliricidia sepium, Leucaena leucocephala, Moringa oleifera and palm nut fibers) in animal production. The experiments were carried out on 128 rabbits divided into 4 batches of 32 animals, reared for 8 weeks under the same conditions. Each batch was subdivided into two subgroups, one fed with a complete diet (a diet containing one of the fiber sources and served all day) and the other with the same diet separated from the fiber source (served at 9 a.m. and supplemented with the fiber source at 4 p.m.). Eight (8) experimental rations were, respectively, tested on the subgroups: complete feed Gliricidia sepium (CFG);supplemented feed Gliricidia sepium (SFG);complete feed Leucaena leucocephala (CFL);supplemented feed Leucaena leucocephala (SFL);complete feed Moringa oleifera (CFM);supplemented feed Moringa oleifera (SFM);complete feed palm nut fiber (CFF);supplemented feed palm nut fiber (SFF). In each subgroup, 4 rabbits were slaughtered at 15 weeks of age for a total of 32 rabbits. Physico-chemical parameters were evaluated on the feed and the meat. Data were analyzed using SAS 2013 software. Fiber content was similar (p > 0.05) for complete feeds. Fat content was high (p < 0.001) for the palm nuts fiber (27.34%) and the CFF feed (11.36%). Feeding rabbits with G. sepium leaves or palm nut fiber continuously increased the fat content of the meat in contrast to sequential feeding. Meat quality was also better when the fiber source was used in the feed of the rabbits in the evening.
文摘The purpose of this study is to compare the results of chemical analysis of two types of activated from the pyrolysis of bull horn and that of cow. Six samples were used to measure pH, carbon, calcium and to determine adsorbent power. The pH was measured at a temperature of 20˚C using an “ANION 7010 ionomer” pH meter, the carbon (C) content was analyzed using a “EURO EA 3000” analyzer. and the electronic balance: “Sartorius CP-2P”, calcium (Ca) was analyzed using a DFS-8 spectrograph. For the adsorbency test, the 0.15% methylene blue R solution was used. At the end of this study, we found that the activated carbon from the bull horn demonstrated a carbon content that is higher than that of the cow horn (20.79% against 15.63%), activated carbon of cow horn is richer in calcium than that of bull horn (16.27% against 3.69%) and then the pH. The cow horn is higher than that of the bull horn (7.43 versus 6.5). For the adsorbent power, the sample (75% bull horn and 25% cow horn) was recorded with the greatest adsorbent power. Thus, from this study, it can be recommended as an activated carbon antidote to be used for poisonings treatment.
文摘This work investigated the removal, kinetics and thermodynamics of iron(II) ions (Fe(II)) by adsorption in static and dynamic conditions in aqueous media on activated carbons (AC-i30min, AC-i1h, and AC-i24h), prepared from palm nut shells collected in the city of Franceville to Gabon, using potassium hydroxide (KOH) as the activating agent. Results on the elimination of Fe(II) in static and dynamic adsorption on prepared activated carbons (ACs) showed that the AC-i24h adsorbent has the best Fe(II) adsorption capacities at saturation (Qsat). The Qsat obtained on AC-i24h in static and dynamic conditions (17.87 and 10.38 mg/g, respectively) were higher than those of AC-i30min (13.89 and 5.54 mg/g respectively) and AC-i1h (14.92 and 8.64 mg/g respectively). Moreover, the static adsorption was more effective in the removal of Fe(II) ions in aqueous media in our experimental conditions. The percentage removal (%E) of Fe(II) obtained on prepared activated carbons in static conditions was better than those obtained in dynamic conditions, especially on AC-i24h, where the %E was 89.27% in static and 61.56% in dynamic. In kinetics, results showed that the pseudo-second-order kinetic model best described the adsorption mechanisms of Fe(II) on prepared activated carbons in static adsorption, with mainly of chemisorption on the solid surfaces. However, in dynamic conditions, the pseudo-first-order kinetic model was more suitable. In addition to the weak interactions between Fe(II) and the activated carbon surfaces, strong interactions (chemisorption) were also observed. Also, thermodynamic data obtained on AC-i24h in static adsorption indicated that the adsorption of Fe(II) was spontaneous and increased with temperature (ΔG˚ H˚ = 503.54 KJ/mol).
